Self-compensating chucking device for infusion pump systems

ABSTRACT

A self-compensating chucking device may be provided. The chucking device may form a portion of a latching door handle of a door of an infusion pump. The door and a housing of the infusion pump may form a clam-shell clamp that secures infusion tubing to pumping mechanisms of the infusion pump. The latching door handle may include a latching door mechanism that includes a tapered pin. The tapered pin may extend through an outer portion of a door housing, an opening in a handle of the door, and into an opening in an inner portion of the door housing. The opening in the handle of the door may have a tapered inner surface that corresponds to the taper the tapered pin to form the chucking device. The pin may include a groove configured to accept an E-clip that retains the tapered pin within the door housing.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/968,741, filed on Dec. 14, 2015, the entirety of which isincorporated herein by reference.

BACKGROUND Technical Field

The present disclosure generally relates to the administration ofmedical fluid by infusion and, in particular, relates to systems andmethods of securing infusion tubing to an infusion pump for providingand pumping medical fluid.

Background

Infusion pumps have become commonplace within the healthcare industry asa devices for precisely administering intravenous (IV) fluids. Use of apump in place of an elevated fluid container with a simple roller clampto control the flow of the IV fluid allows more accurate and consistentcontrol of the rate of delivery of the fluid to the patient.

The assembly of tubing, valves, fittings, and needles that connect thefluid container to the patient may be referred to as an “IV set.” IVsets are typically disposable to reduce the risk of infection andcontamination. When used with an infusion pump, the IV set includes asegment intended to be manipulated by the pump to cause the fluid toflow at a controlled rate. For a peristaltic type of pump, this may beas simple as a length of tubing that is captured between two halves of aclam-shell style pumping mechanism to fit the tubing into a pumpingcompartment.

SUMMARY

An improved latching door mechanism is provided. The improved latchingdoor mechanism may be provided for a clam-shell door for capturing IVtubing in an intravenous infusion pump system for secure, reliable,positioning of the tubing over many uses of the pump system. Thelatching door mechanism may include a latch having a self-adjustingchucking mechanism that helps ensure secure, reliable latching of thedoor over the lifetime of the pump. The latching door mechanism mayinclude a tapered pin configured to support, mechanically retain, andallow rotational pivoting of a latching door handle, by interaction witha complimentary tapered hole mating interface.

Certain exemplary embodiments of the present disclosure include aninfusion pump, including: a housing; at least one pumping mechanism; anda pivoting door configured to close and latch to secure infusion tubingto the at least one pumping mechanism, wherein the pivoting doorincludes: a handle having recess and an opening in the recess; a doorhousing having an inner portion and an outer portion; and a tapered pinthat extends through an opening in the outer portion, a co-alignedopening in the recess of the handle, and a co-aligned opening in theinner portion.

In another embodiment, a latching door handle assembly for a door of aninfusion pump is disclosed that includes a molded handle having a hookportion with a recess and a tapered opening in the recess; and a taperedpin, wherein the tapered pin includes: a tapered portion configured toengage in the tapered opening; and a groove configured to receive anE-clip disposed in the recess.

In another embodiment, a fluid infusion system is provided thatincludes: an intravenous (IV) set having IV tubing; and an IV pumphaving a pumping module and a door, wherein a pumping segment of the IVtubing is secured to the pumping module by the door, and wherein thedoor includes: a door housing having an outer portion, an inner portion,and an air gap between the outer portion and the inner portion; a handlehaving a tapered opening disposed in the air gap; and a latching doorhandle assembly that includes a tapered pin that extends through anopening in the outer portion, through the tapered opening in the airgap, and into a co-aligned opening in the inner portion.

It is understood that various configurations of the subject technologywill become readily apparent to those skilled in the art from thedisclosure, wherein various configurations of the subject technology areshown and described by way of illustration. As will be realized, thesubject technology is capable of other and different configurations andits several details are capable of modification in various otherrespects, all without departing from the scope of the subjecttechnology. Accordingly, the summary, drawings and detailed descriptionare to be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide furtherunderstanding and are incorporated in and constitute a part of thisspecification, illustrate disclosed embodiments and together with thedescription serve to explain the principles of the disclosedembodiments. In the drawings:

FIG. 1 is a diagram of a system for administering medical fluid to apatient using an IV pump according to certain aspects of the presentdisclosure.

FIG. 2 illustrates a pumping segment of an IV set fitting into the pumpmodule of the IV pump of FIG. 1 according to certain aspects of thepresent disclosure.

FIG. 3A illustrates a perspective view of an infusion pump with a doorin an open position and showing part of a pumping segment of an IV setfitting into the pump module of the infusion pump according to certainaspects of the present disclosure.

FIG. 3B illustrates a front view of the infusion pump of FIG. 3Aaccording to certain aspects of the present disclosure.

FIG. 4A is a perspective view of the infusion pump of FIG. 3A, with thedoor in a closed and unlatched position according to certain aspects ofthe present disclosure.

FIG. 4B is a perspective view of the infusion pump of FIG. 3A, with thedoor in a closed and latched position according to certain aspects ofthe present disclosure.

FIG. 5 illustrates an exploded perspective view of a door and latchassembly for an infusion pump according to certain aspects of thepresent disclosure.

FIG. 6 illustrates an exploded perspective view of a latching doorhandle assembly according to certain aspects of the present disclosure.

FIG. 7 illustrates a cross-sectional top view of an assembled latchassembly according to certain aspects of the present disclosure.

FIG. 8 illustrates a cross-sectional view of a tapered pin for a latchassembly according to certain aspects of the present disclosure.

FIG. 9 illustrates a cross-sectional top view of an assembled latchassembly showing various exemplary load forces on the assembly duringoperation according to certain aspects of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below describes variousconfigurations of the subject technology and is not intended torepresent the only configurations in which the subject technology may bepracticed. The detailed description includes specific details for thepurpose of providing a thorough understanding of the subject technology.Accordingly, dimensions may be provided in regard to certain aspects asnon-limiting examples. However, it will be apparent to those skilled inthe art that the subject technology may be practiced without thesespecific details. In some instances, well-known structures andcomponents are shown in block diagram form in order to avoid obscuringthe concepts of the subject technology.

It is to be understood that the present disclosure includes examples ofthe subject technology and does not limit the scope of the appendedclaims. Various aspects of the subject technology will now be disclosedaccording to particular but non-limiting examples. Various embodimentsdescribed in the present disclosure may be carried out in different waysand variations, and in accordance with a desired application orimplementation.

In the following detailed description, numerous specific details are setforth to provide a full understanding of the present disclosure. It willbe apparent, however, to one ordinarily skilled in the art thatembodiments of the present disclosure may be practiced without some ofthe specific details. In other instances, well-known structures andtechniques have not been shown in detail so as not to obscure thedisclosure.

While the following discussion is directed to the administration ofmedical fluid to a patient by a nurse using an IV pump, the disclosedmethods and configurations may be used for other medical and non-medicalapplications and may be used by other individuals, for example a patientself-administering a medical fluid at home.

FIG. 1 is a diagram of a system 100 for administering medical fluid to apatient 10 using an IV pump 12. As shown in FIG. 1, a fluid container 14may be hung at or above the patient's head and connected via an IV set18 to an IV pump 12 and then to the patient 10. In this example, the IVpump 12 includes a control module 16 and a pumping module 20. A portionof IV set 18 may be secured to pumping module 20 by a door 30. Door 30may be a pivoting door that is rotatable about hinge portions 60 and maybe provided with a latching mechanism 37 operable to securely fastendoor 30 in a closed position to secure the portion of the IV set inposition for pumping. Latching mechanism 37 may also be operable torelease door 30 so that door 30 can pivot to an open position to releaseIV set 18.

FIG. 2 illustrates a pumping segment 17 of IV set 18 that may be securedinto the pump module 20 of the IV pump 12 of FIG. 1. In this example,pumping element 17 is a length of the tubing of IV set 18. The pumpingmodule 20 is shown with its front door 30 opened and the inner surface21 of door 30 and the pumping actuators 19 of pump module 20 visible.When installed, the pumping element 17 is located against the pumpingactuators 19 and door 30 can be closed and latched using an internalmember 23 of latch 37 to secure pumping element 17 against pumpingactuators 19. Pumping actuators 19 may be operated to sequentiallycompress portions of pumping element 17 to apply force to the fluid andsequentially advance fluid toward the patient 10 at a controlled flowrate.

An exemplary implementation of infusion pump 12 is shown in FIGS. 3A,3B, 4A and 4B. As shown in FIGS. 3A, 3B, 4A and 4B, an infusion pump ofa fluid infusion system may include a housing 27 which accommodates oneor more pumping mechanisms (e.g., a cam mechanism that controls aplurality of fingers of a peristaltic pumping mechanism, an electricmotor and associated gearing that drive said cam mechanism) and furtheraccommodates electronic control and processing circuitry for controllingthe pumping mechanisms and processing signals (e.g., from pressuresensors, etc.) provided on the unit.

The pump unit 12, as shown in FIGS. 4A and 4B, may also include anelectronically operated display 52, an alarm light 54, an input keyboard56 or other manually operated controls. The rear of the unit 12 (notshown) may be provided with various connectors including connectors forreceiving complementary power supply connectors, electroniccommunications interfacing connectors for providing data and alarmoutput signals and for receiving input signals, and/or mechanicalsupports.

In the example of FIG. 3A, the front of the housing 27 includes a faceor deck 29 on which is exposed an upper mounting or bracket 22 for acomplementary fitting 38 forming part of an infusion line; a lowermounting or bracket 24 for a complementary fitting 40 forming part ofsuch infusion line and a peristaltic assembly 26 which is, effectively,the operative end of the peristaltic pumping mechanism and may, inprinciple, be the free ends of respective fingers moveable, by the cammechanism referred to, inwards and outwards from the face or deck 29.

In order to make it easier to maintain sterile conditions, these fingersmay be covered by a thin flexible membrane (not shown) sealed at itsedges with respect to the deck 29. Door 30 is may be fitted to thehousing 27 and can be swung between an open position illustrated inFIGS. 3A and 3B and a closed position illustrated in FIGS. 4A and 4B,about a pivotal axis A.

A medical fluid infusion line, for use with the pump unit, may includeupper and lower sections 32 and 34 respectively of transparent (e.g.,plastic) tubing, an intermediate section 36 of resiliently compressibletubing, (e.g., formed from silicone rubber), and upper and lowerfittings 38 and 40 via which the tubing section 36 is connectedrespectively with the upper line 32 and with the lower line 34. In use,the upper line 32 may extend upwardly to a source 14 of the medicalfluid to be administered and the lower line 34 may extend from theinfusion pump to an infusion needle or catheter or the like insertedinto the patient 10. In use, the infusion line may be extended acrossthe face or deck 29 of the pump unit so that the fittings 38 and 40 arereceived in the brackets 22 and 24 respectively and so that the tubingsection 36 extends over the peristaltic assembly 26 as illustrated inFIGS. 3A and 3B.

The infusion line may be fitted in place in this fashion while door 30is in the open position shown in FIGS. 3A and 3B. After the infusionline has been so fitted, door 30 may be moved to the closed positionshown in FIG. 4A and secured using catch 37 which comprises a levermounted on the outer edge of the door 30 (e.g., the edge which lies atthe side of the pump unit when the door is in its closed position), by apin 300 for pivoting about an axis B (see, e.g., FIG. 4A) that isgenerally perpendicular to that outer edge of the door and parallel withthe front face of the door.

As shown in FIG. 4A, catch 37 may have a handle portion 37 b whichextends downwardly and into a pocket in the front of the door 30. Catch37 may also include a cam portion (described in further detailhereinafter) adapted to fit within a complementary recess 39, in deck 29and obscured by the outer housing 27, at the front right of the pumphousing adjacent side of the pump.

The cam portion of the catch 37 may have a cam surface 502, (see FIG.5), configured to engage under an internal yoke boss 41 or othercorresponding cam feature (which projects laterally from the pumphousing into recess 39) when, with the pump door 30 closed, the handleportion 37 b is swung downwardly and rearwardly from a position in whichit projects forwards and outwards from the door (FIG. 4A) to a positionin which the handle portion 37 b lies against the front of the door(FIG. 4B).

In operation of the pump, the fingers of the peristaltic assembly 26periodically press the flexible resilient tubing against a countersurface or anvil to propel fluid within the infusion line along thelatter. In one exemplary implementation of the pump, the peristalticassembly comprises an upper finger and a lower finger, which are of arelatively limited extent in the longitudinal direction of the infusionline, and an intermediate finger or pad, between the upper and lowerfingers, in which the intermediate finger is extended or elongated inthe longitudinal direction of the infusion line.

In operation, assuming the fluid is to be propelled downwards, as viewedin FIGS. 1 to 4B, along the infusion line, the peristaltic assemblyperforms a repeating cycle in which, with the intermediate pad spacedfrom the counter surface, the upper finger presses the flexible tubeagainst the counter surface or anvil to close the tube at the locationof the upper finger, the lower finger is then withdrawn from the countersurface to open the tube at the location of the lower finger. Then theintermediate pad or finger is then moved towards the counter surface todrive the fluid in the tube adjacent the intermediate pad downward alongthe tube, and then the tube is pinched closed again between the lowerfinger and the counter surface. The upper finger is then withdrawn fromthe counter surface and the intermediate finger withdrawn from thecounter surface to draw fresh fluid into the part of the tube adjacentthe intermediate finger. It should be appreciated that the pumpingmechanisms described above in connection with FIGS. 3A-4B are merelyillustrative. Other pumping arrangements or mechanisms can be used topump fluid through infusion tubing (or any other portion of an IV setsuch as an infusion cassette) that is secured to the pumping mechanismsby a pivoting clam-shell door that is controllable and latchable using alatch mechanism as described herein.

FIG. 5 shows an example of a door assembly 30 having an improvedlatching door mechanism with a tapered pin 300 designed to support,mechanically retain and allow rotational pivoting of a latching doorhandle 37 b, with a complimentary tapered hole mating interface 530 inthe door handle. Tapered pin 300 may be formed from a hardened steel inone embodiment (e.g., an AISI Type 303 Stainless Steel).

An intravenous infusion pump may operate by capturing a fluid deliverytube between two halves of a clam-shell-style pumping mechanism. Onehalf of this clam-shell pump configuration may be a base assembly thathouses the primary electro-mechanical pump elements, hinge mountingpoints to support a door assembly, features that capture and locate thefluid delivery tube and a yoke catch that engages a latching door handlefor snug door closure.

Door assembly 30 of FIG. 5 may be coupled to housing 27 of an infusionpump at hinge points 60 to form the second half of a clam-shell pumpconfiguration that mounts to, and rotates about, the hinge mountingpoints of the other half of the clam shell formed by the housing 27.Door assembly 30 may include, on a rear side (not shown) complimentaryfeatures to the pump features of the housing that capture and locate thefluid delivery tube along the mechanical pump elements. Door assembly 30may include a rotationally pivoted latching door handle 37 b that mateswith the yoke clamp of the housing, thus allowing this snug doorclosure.

Tapered pin 300, when installed in the door latch assembly may span anair gap 511 of a rectangular shaped aperture in the door assembly'shousing 504 at which the latching door handle 37 b is located andsupported. The air gap 511 may be disposed between an inner portion 520and an outer portion 522 of door housing 504. During assembly, thetapered pin 300 may be inserted through a series of mating holes in thefollowing order: a through-hole 508 in outer portion 522, a matching,co-aligned tapered hole 530 in the hook portion 500 of the latching doorhandle 37 b, and a co-aligned blind hole 510 in the inner portion 520 ofdoor housing 504.

Door handle 37 b may be a sintered steel handle such as a moldedsintered stainless steel handle with a molded hook 500 and a recess 540.Opening 530 may be disposed in recess 540 and may have a tapered innersurface that corresponds to the shape of a tapered outer surface oftapered pin 300. The tapered inner surface of opening 530 may have anapproximately 2 degree taper moving inward in a direction from outerportion 522 toward inner portion 520 of housing 504, when door assembly30 is assembled. A taper interface (e.g., a 2.0 degree taper interface)may be formed from the inclined contact surface made between the taperedpivot latch pin 300 and the interior surface of opening 530 of hookportion 500. Side torque applied to the door handle 37 b during closinggenerates a chucking force along this inclined tapered surfacetemporarily binding the pivot latch pin and hook together. Simultaneousdownward rotation during this “chucking” enables the door handle toproperly engage the pump housing thus enabling door closure.

Door housing 504 may be formed from plastic and may include co-alignedopenings 508 and 510, respectively, in outer portion 522 and innerportion 520. An inner wall of outer portion 522 and an outer wall ofinner portion 520 may form opposing surfaces of the aperture 511 withinwhich pin 300 engages hole 530 of handle 37 b.

As shown, a wear protection washer such as washer 512 and the coil of atorsion spring such as spring 514 may be disposed in recess 540 whendoor assembly 30 is assembled. In the example of FIG. 5, washer 512includes a retention tab 513 that keys the washer into a gap betweenrecess 540 (e.g., a latch handle spring pocket) and spring 514. However,this is merely illustrative. In some embodiments, washer 512 may beimplemented as a flat washer. According to an embodiment, torsion spring514 extends around the tapered opening in recess 540, washer 512 isdisposed on the tapered pin, and E-clip retainer 506 disposed in thee-clip groove 602 between torsion spring 514 and the wear protectionwasher 512.

As shown in the exploded perspective view of latching door handleassembly 650 of FIG. 6, features along the body of tapered pin 300 maybe provided to securely retain and establish the rotational datum of thelatching door handle 37 b within the door housing 504. These tapered pinfeatures include the tapered profile geometry of a tapered portion 600of the pin 300 and an E-clip groove 602.

Tapered section 600 of pin 300 may be configured to mate with a matchingtapered inner surface of opening 530 in the hook portion 500 of thelatching door handle 37 b. As a turning force is applied to the handle37 b, in the un-latched position, to close the door, these two taperedmating features are pushed together (e.g., by a lateral force generatedalong the tapered interface by turning the handle as the door latch camsurface 502 of handle 37 b and a corresponding cam feature in the pumphousing are moved into alignment preceding the downward handle camlatching upon a housing catch such as a yoke boss) thereby generating abinding axial friction between pin 300 and the inner surface of opening530 that binds the pin 300 and handle 37 b together along this taperedinterface.

During closure, as the door is turned, engagement with the internalcomponents of the pump that capture the tube set resist this doorclosure, prompting an increase in side turning force to allow alignmentof the cam latching elements. Turning force on the door handle 37 b, toovercoming the resistance of the internal components of the pump,generates the binding axial friction along the tapered interface 600 andthe matching tapered inner surface of opening 530 that temporarily locksthe pin 300 and latch door handle 37 b together creating a stablerotational pivot axis. This stable pivot axis enables smooth alignedmotion between hook 500 of latching door handle 37 b and the yoke catch(e.g., a boss) of the housing when the handle is pushed (e.g., downward)to close and latch the door 30.

E-clip groove 602 may be a recess having a complementary shape foraccepting E-Clip retainer 506. E-clip retainer 506, when engaged ingroove 602 in pin 300, provides a mechanical stop that prevents taperedpin 300 from backing out of door housing 504 during normal operation.When door assembly 30 is assembled, E-clip 506 is located along thetapered pin 300 near the inner surface of the outer portion 522 of thedoor housing aperture 511. A washer 512 may be placed between E-Clip 506and the inner surface of outer portion 522 to provide a smooth surfacethat protects E-clip 506 from damage caused by chaffing against the doorhousing inner wall. E-clip retainer 506 may, for example, be a Rotoclip®retainer in some embodiments.

For ease of removal from door housing 504 during maintenance and repairoperations, a threaded extraction hole 604 may be provided at theexposed end of tapered pin 300. A threaded rod or tool can be insertedinto this hole 604 and used to pull pin 300 out of the door housing 504.The extraction hole 604 may be provided with an internal thread (e.g., a#2-56 UNC-2B internal thread). In this way, the extraction hole 604allows one to pull symmetrically along the tapered pin's axis, enablingeasy extraction of the pin during repair or maintenance operations.E-Clip retainer 506 may be removed before engaging the hole 604 toremove the pin 300.

As shown in FIG. 6, handle 37 b may include one or more latchingextensions such as latching extensions 620. Latching extensions 620 mayextend into or below a portion of housing 27 and engage withcorresponding mating features of the tube set as part of the infusiontube set functionality in accordance with the pumping mechanisms of pump12.

Pin 300 may be provided with e-clip recess 602 and without anyadditional recess as in the example of FIG. 6. Latching extensions 620are shown in FIG. 6 along with mating features 629 for latchingextensions 620 on an interior side of handle 37 b.

FIG. 7 is a cross-sectional top view of the latch assembly of door 30 inan assembled configuration, in accordance with an embodiment. In theexample of FIG. 7, pin 300 extends through opening 508 in outer portion522 of housing 504, through opening 530 in recess 540, and partiallyinto opening 510 in inner portion 520 of housing 504. As shown in theexample of FIG. 7, opening 510 may be a blind hole in inner portion 520.Also shown in FIG. 7 is washer 512 disposed between the door housingwall 700 and E-clip retainer 506 along tapered pivot latch pin 300. Inthis configuration, washer 512 prevents contact between door wall 700and E-clip 506 and provides a smooth surface for E-clip 506 to oscillateagainst, thereby reducing or eliminating E-Clip stretch wear.

As shown in FIG. 7, pin 300 may be provided with a wear-relief featuresuch as wear-relief chamfer 704 that prevents pin 300 from coming intocontact with the inner wall 706 of housing 504 if, over time, pin creepis present. For example, in configurations in which pin 300 is ahardened steel pin and hook portion 500 is formed from a relativelysofter molded sintered steel, pin creep may arise when the hardenedsteel tapered pin is pushed into the relatively softer sintered steelhook, during “chucking”, thereby deforming the hook's tapered hole 530.However, the tapered interface formed by tapered portion 600 and theinner surface of tapered hole 530 may provide a self-compensatingchucking device that self-compensates for pin creep by allowing pin 300to move deeper into hole 530 such that a wider portion of the taperedsurface of pin 300 engages the deformed hole 530 to provide the samebinding friction.

As shown in FIG. 7, an air gap 702 may be provided between the inner end708 of pin 300 and the bottom 710 of opening 510 that allows pin 300 tomove deeper into openings 530 and 510 without the pin bottoming out inopening 510. As shown, the tapered portion of the tapered pin 300 ispartially disposed in the opening 530 in the recess 540 of the handle 37b and extends from the opening 530 in the recess 540 of the handle 37 binto the recess 540 so that the tapered portion 600 can move furtherinto opening 530 in the presence of pin creep.

Wear-relief chamfer 704 may, for example, be a 10-15 mil chamfer thatcan accommodate, for example, 3-5 mils of wear over the lifetime ofassembly 650. As shown in FIG. 7, wear-relief chamfer 704 may bedisposed adjacent an inner edge of the opening 530 in the recess 540 ofthe handle 37 b.

The tapered interface between pin 300 and opening 530 may thus establisha stable, self-centering, self-compensating, axial alignment between thechucking assembly's mating components thereby allowing smooth repeatablemotion of door handle 37 b over repeated opening and closing of door 30.

FIG. 8 is an enlarged view of a portion of pin 300 engaged in opening530 in hook portion 500. Other portions of door assembly 30 are omittedfrom FIG. 8 to facilitate viewing of tapered interface 800 formed fromthe outer surface of tapered portion 600 of pin 300 and the innersurface of opening 530. As shown by dashed lines 806A and 806B, taperedinterface 800 may define a taper of angle α. Angle α may, for example,be a two-degree angle, an angle of less than two degrees (e.g., aone-degree angle, a 1.5 degree angle, or a 1.8 degree angle), or anangle of more than two degrees (e.g., a 2.5 degree angle, a three degreeangle, a four degree angle, or a five degree angle).

As shown in FIG. 8, groove 602 may be formed between a cylindrical outerportion 801 of pin 300 and an annular extension 803 of pin 300. Annularextension 803 may be disposed between groove 602 and tapered portion 600of pin 300.

Contact at the interface 800 along a length of tapered portion 600 mayalso prevent or limit lateral play of pin 300 within opening 530 so thata perpendicular bisector (e.g., as indicated by arrow 804) of the outersurface of portion 600 that passes through the axis of pin 300 is notdisplaced, even in the presence of forces on pin 300 that wouldotherwise cause non-axial rotation of pin 300 within opening 530.

The frictional binding load generated by the chucking tapered interface800 (as indicated, for example, by arrows 802) may provide theadvantages over conventional systems of eliminating the need for athread-lock adhesive and providing a tapered interface that breaks awayeasily when the assembly is relaxed and in a non-chucking state allowingthe assembly to be separable and thereby enabling reuse of components(as examples).

FIG. 9 is a cross-sectional top view of the latch assembly of door 30 inan assembled configuration and showing various load forces on theassembly, in accordance with an embodiment. The example of FIG. 9 is afree body diagram showing how the “chucking” effect is generated. Thecross-section of FIG. 9 shows a cross-section of the portion of pumpmodule 20 referenced by the dashed circle 459 shown in FIG. 4A.

As shown in FIG. 9, a handle closure load 900 may be generated on handle37 b during closing that pushes outwardly on the handle. However, pin300, in cooperation with e-clip 506, provide a pin counter force 902 inopposition to the load 900, thus generating the tapered interfacechucking force indicated by arrows 802. In this way, the tapered pin andthe tapered opening are configured such that a door closing force on thedoor that is sufficient to overcome resistance from internal componentsof the IV pump that capture the IV tubing and sufficient to place thecam surface in alignment with the corresponding cam feature generates alateral force along the tapered pin and tapered opening that pushes anouter tapered surface of the tapered pin into and along a tapered innersurface of the tapered opening causing chucking or binding.

The tapered pin and the tapered opening can thus be configured tocontinuously slide along a tapered inclined interface to compensate forwear and maintain a binding or chucking condition that absorbs slacknessor looseness resulting from a gradual wear of the tapered opening bycontact with the tapered pin.

Extraction hole 604 may provide for ease of disassembly during doormaintenance and may provide a unique identity feature for pin 300.Moreover, a tapered interface configuration as described herein isdifficult to counterfeit as the mating component's taper geometry istightly controlled during the machining processes. As such, deviationsfrom the specified tolerances between tapered mating parts will preventproper component interaction and mechanism function.

The subject technology is illustrated, for example, according to variousaspects described above. Various examples of these aspects are describedas numbered concepts or clauses (1, 2, 3, etc.) for convenience. Theseconcepts or clauses are provided as examples and do not limit thesubject technology. It is noted that any of the dependent concepts maybe combined in any combination with each other or one or more otherindependent concepts, to form an independent concept. The following is anon-limiting summary of some concepts presented herein:

Concept 1. An infusion pump, comprising:

a housing;

at least one pumping mechanism; and

a pivoting door configured to close and latch to secure infusion tubingto the at least one pumping mechanism, wherein the pivoting doorcomprises:

-   -   a handle having recess and an opening in the recess;    -   a door housing having an inner portion and an outer portion; and    -   a tapered pin that extends through an opening in the outer        portion, a co-aligned opening in the recess of the handle, and a        co-aligned opening in the inner portion.        Concept 2. The infusion pump of Concept 1 or any other Concept,        wherein the opening in the recess of the handle comprises a        tapered opening having a tapered inner surface with a taper that        corresponds to a taper of the tapered pin.        Concept 3. The infusion pump of Concept 2 or any other Concept,        wherein the tapered pin comprises a tapered portion and a        cylindrical portion and wherein the cylindrical portion is        disposed within the opening in the outer portion of the door        housing.        Concept 4. The infusion pump of Concept 3 or any other Concept,        wherein the tapered portion of the tapered pin is partially        disposed in the opening in the recess of the handle and extends        from the opening in the recess of the handle into the recess.        Concept 5. The infusion pump of Concept 4 or any other Concept,        wherein the tapered pin further comprises a groove disposed        between the cylindrical portion and the tapered portion.        Concept 6. The infusion pump of Concept 5 or any other Concept,        further comprising an E-clip retainer engaged in the groove that        provides a mechanical stop that prevents the tapered pin from        backing out of door housing.        Concept 7. The infusion pump of Concept 6 or any other Concept,        wherein the tapered pin comprises a wear-relief chamfer adjacent        an edge of the opening in the recess of the handle.        Concept 8. The infusion pump of Concept 7 or any other Concept,        further comprising an air gap between an end of the tapered pin        and a bottom of the opening in the inner portion of the door        housing.        Concept 9. The infusion pump of Concept 8 or any other Concept,        further comprising a washer disposed between the E-clip retainer        and an inner wall of the outer portion of the housing.        Concept 10. The infusion pump of Concept 1 or any other Concept,        wherein the tapered pin comprises a tapered portion having a        taper of approximately two degrees.        Concept 11. The infusion pump of Concept 10 or any other        Concept, wherein the opening in the recess of the handle        comprises a corresponding taper of approximately two degrees.        Concept 12. The infusion pump of Concept 1 or any other Concept,        wherein the handle comprises a sintered steel handle and wherein        the tapered pin comprises a relatively harder hardened steel        pin.        Concept 13. The infusion pump of Concept 12 or any other        Concept, wherein the handle comprises a hook portion, wherein        the recess is disposed in the hook portion, and wherein the hook        portion comprises a cam surface.        Concept 14. The infusion pump of Concept 13 or any other        Concept, further comprising a boss disposed on the housing, the        boss configured to engage with the cam surface of the hook        portion of the handle to press the tapered pin into the opening        in the recess in the hook portion when the cam surface is        pressed against the boss by a closing force on the handle.        Concept 15. The infusion pump of Concept 1 or any other Concept,        further comprising a threaded extraction hole in the tapered        pin.        Concept 16. A latching door handle assembly for a door of an        infusion pump, comprising:

a molded handle having a hook portion with a recess and a taperedopening in the recess; and

a tapered pin, wherein the tapered pin comprises:

-   -   a tapered portion configured to engage in the tapered opening;        and    -   a groove configured to receive an E-clip disposed in the recess.        Concept 17. The latching door handle assembly of Concept 16 or        any other Concept, further comprising a cam surface on the hook        portion, wherein the cam surface is configured to transfer a        force on the cam surface into a force that presses the tapered        pin into the tapered opening.        Concept 18. The latching door handle assembly of Concept 16 or        any other Concept, further comprising:

a torsion spring that extends around the tapered opening in the recess;and

a washer on the tapered pin; and

the E-clip disposed in the groove between the torsion spring and thewasher.

Concept 19. A fluid infusion system, comprising:

an intravenous (IV) set having IV tubing; and

an IV pump having a pumping module and a door, wherein a pumping segmentof the IV tubing is secured to the pumping module by the door, andwherein the door comprises:

-   -   a door housing having an outer portion, an inner portion, and an        air gap between the outer portion and the inner portion;    -   a handle having a tapered opening disposed in the air gap; and    -   a latching door handle assembly that includes a tapered pin that        extends through an opening in the outer portion, through the        tapered opening in the air gap, and into a co-aligned opening in        the inner portion.        Concept 20. The fluid infusion system of Concept 19 or any other        Concept, wherein the latching door handle assembly further        comprises:

a hook portion having a cam surface configured to engage a correspondingcam feature on the pumping module;

an E-clip retainer engaged with a recess on the tapered pin;

a washer disposed between the E-clip retainer and the outer portion ofthe door housing; and

a torsion spring disposed between the E-clip retainer and a portion ofthe handle.

Concept 21. The fluid infusion system of Concept 20 or any otherConcept, wherein the tapered pin and the tapered opening are configuredsuch that a door closing force on the door that is sufficient toovercome resistance from internal components of the IV pump that capturethe IV tubing and to place the cam surface in alignment with thecorresponding cam feature generates a lateral force along the taperedpin and tapered opening that pushes an outer tapered surface of thetapered pin into and along a tapered inner surface of the taperedopening causing chucking or binding.Concept 22. The fluid infusion system of Concept 21 or any otherConcept, wherein the tapered pin and the tapered opening are configuredto continuously slide along a tapered inclined interface to compensatefor wear and maintain a binding or chucking condition that absorbsslackness or looseness resulting from a gradual wear of the taperedopening by contact with the tapered pin.

The present disclosure is provided to enable any person skilled in theart to practice the various aspects described herein. The disclosureprovides various examples of the subject technology, and the subjecttechnology is not limited to these examples. Various modifications tothese aspects will be readily apparent to those skilled in the art, andthe generic principles defined herein may be applied to other aspects.

A reference to an element in the singular is not intended to mean “oneand only one” unless specifically so stated, but rather “one or more.”Unless specifically stated otherwise, the term “some” refers to one ormore. Pronouns in the masculine (e.g., his) include the feminine andneuter gender (e.g., her and its) and vice versa. Headings andsubheadings, if any, are used for convenience only and do not limit theinvention.

The word “exemplary” is used herein to mean “serving as an example orillustration.” Any aspect or design described herein as “exemplary” isnot necessarily to be construed as preferred or advantageous over otheraspects or designs. In one aspect, various alternative configurationsand operations described herein may be considered to be at leastequivalent.

As used herein, the phrase “at least one of” preceding a series ofitems, with the term “or” to separate any of the items, modifies thelist as a whole, rather than each item of the list. The phrase “at leastone of” does not require selection of at least one item; rather, thephrase allows a meaning that includes at least one of any one of theitems, and/or at least one of any combination of the items, and/or atleast one of each of the items. By way of example, the phrase “at leastone of A, B, or C” may refer to: only A, only B, or only C; or anycombination of A, B, and C.

A phrase such as an “aspect” does not imply that such aspect isessential to the subject technology or that such aspect applies to allconfigurations of the subject technology. A disclosure relating to anaspect may apply to all configurations, or one or more configurations.An aspect may provide one or more examples. A phrase such as an aspectmay refer to one or more aspects and vice versa. A phrase such as an“embodiment” does not imply that such embodiment is essential to thesubject technology or that such embodiment applies to all configurationsof the subject technology. A disclosure relating to an embodiment mayapply to all embodiments, or one or more embodiments. An embodiment mayprovide one or more examples. A phrase such an embodiment may refer toone or more embodiments and vice versa. A phrase such as a“configuration” does not imply that such configuration is essential tothe subject technology or that such configuration applies to allconfigurations of the subject technology. A disclosure relating to aconfiguration may apply to all configurations, or one or moreconfigurations. A configuration may provide one or more examples. Aphrase such a configuration may refer to one or more configurations andvice versa.

In one aspect, unless otherwise stated, all measurements, values,ratings, positions, magnitudes, sizes, and other specifications that areset forth in this specification, including in the claims that follow,are approximate, not exact. In one aspect, they are intended to have areasonable range that is consistent with the functions to which theyrelate and with what is customary in the art to which they pertain.

It is understood that the specific order or hierarchy of steps, oroperations in the processes or methods disclosed are illustrations ofexemplary approaches. Based upon implementation preferences orscenarios, it is understood that the specific order or hierarchy ofsteps, operations or processes may be rearranged. Some of the steps,operations or processes may be performed simultaneously. In someimplementation preferences or scenarios, certain operations may or maynot be performed. Some or all of the steps, operations, or processes maybe performed automatically, without the intervention of a user. Theaccompanying method claims present elements of the various steps,operations or processes in a sample order, and are not meant to belimited to the specific order or hierarchy presented.

All structural and functional equivalents to the elements of the variousaspects described throughout this disclosure that are known or latercome to be known to those of ordinary skill in the art are expresslyincorporated herein by reference and are intended to be encompassed bythe claims. Moreover, nothing disclosed herein is intended to bededicated to the public regardless of whether such disclosure isexplicitly recited in the claims. No claim element is to be construedunder the provisions of 35 U.S.C. § 112 (f) unless the element isexpressly recited using the phrase “means for” or, in the case of amethod claim, the element is recited using the phrase “step for.”Furthermore, to the extent that the term “include,” “have,” or the likeis used, such term is intended to be inclusive in a manner similar tothe term “comprise” as “comprise” is interpreted when employed as atransitional word in a claim.

The Title, Background, Summary, Brief Description of the Drawings andAbstract of the disclosure are hereby incorporated into the disclosureand are provided as illustrative examples of the disclosure, not asrestrictive descriptions. It is submitted with the understanding thatthey will not be used to limit the scope or meaning of the claims. Inaddition, in the Detailed Description, it can be seen that thedescription provides illustrative examples and the various features aregrouped together in various embodiments for the purpose of streamliningthe disclosure. This method of disclosure is not to be interpreted asreflecting an intention that the claimed subject matter requires morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter lies in less than allfeatures of a single disclosed configuration or operation. The followingclaims are hereby incorporated into the Detailed Description, with eachclaim standing on its own as a separately claimed subject matter.

The claims are not intended to be limited to the aspects describedherein, but are to be accorded the full scope consistent with thelanguage of the claims and to encompass all legal equivalents.Notwithstanding, none of the claims are intended to embrace subjectmatter that fails to satisfy the requirement of 35 U.S.C. § 101, 102, or103, nor should they be interpreted in such a way.

What is claimed is:
 1. A latching door handle assembly for a door of aninfusion pump, comprising: a molded handle having a hook portion with arecess and a tapered opening in the recess; and a tapered pin, whereinthe tapered pin comprises: a tapered portion configured to engage in thetapered opening; and a groove configured to receive an E-clip disposedin the recess.
 2. The latching door handle assembly of claim 1, whereinthe tapered opening comprises a tapered inner surface with a taper thatcorresponds to a taper of the tapered pin.
 3. The latching door handleassembly of claim 2, wherein the tapered pin comprises a tapered portionand a cylindrical portion.
 4. The latching door handle assembly of claim3, wherein the tapered portion of the tapered pin is partially disposedin the opening in the recess of the handle and extends from the openingin the recess of the handle into the recess.
 5. The latching door handleassembly of claim 1, wherein the tapered pin comprises a tapered portionhaving a taper of approximately two degrees.
 6. The latching door handleassembly of claim 1, wherein the handle comprises a sintered steelhandle and wherein the tapered pin comprises a relatively harderhardened steel pin.
 7. The latching door handle assembly of claim 1,further comprising a cam surface on the hook portion, wherein the camsurface is configured to transfer a force on the cam surface into aforce that presses the tapered pin into the tapered opening.
 8. Thelatching door handle assembly of claim 7, further comprising a bossdisposed on the infusion pump, the boss configured to engage with thecam surface of the hook portion of the handle to press the tapered pininto the opening in the recess in the hook portion when the cam surfaceis pressed against the boss by a closing force on the handle.
 9. Thelatching door handle assembly of claim 1, further comprising: a torsionspring that extends around the tapered opening in the recess; and awasher on the tapered pin; and the E-clip disposed in the groove betweenthe torsion spring and the washer.
 10. The latching door handle assemblyof claim 9, further comprising a washer disposed between the E-clip andan inner wall of an outer portion of the infusion pump.
 11. A fluidinfusion system, comprising: an intravenous (IV) set having IV tubing;and an IV pump having a pumping module and a door, wherein a pumpingsegment of the IV tubing is secured to the pumping module by the door,and wherein the door comprises: a door housing having an outer portion,an inner portion, and an air gap between the outer portion and the innerportion; a handle having a tapered opening disposed in the air gap; anda latching door handle assembly that includes a tapered pin that extendsthrough an opening in the outer portion, through the tapered opening inthe air gap, and into a co-aligned opening in the inner portion.
 12. Thefluid infusion system of claim 11, wherein the latching door handleassembly further comprises: a hook portion having a cam surfaceconfigured to engage a corresponding cam feature on the pumping module;an E-clip retainer engaged with a recess on the tapered pin; a washerdisposed between the E-clip retainer and the outer portion of the doorhousing; and a torsion spring disposed between the E-clip retainer and aportion of the handle.
 13. The fluid infusion system of claim 12,wherein the tapered pin and the tapered opening are configured such thata door closing force on the door that is sufficient to overcomeresistance from internal components of the IV pump that capture the IVtubing and to place the cam surface in alignment with the correspondingcam feature generates a lateral force along the tapered pin and taperedopening that pushes an outer tapered surface of the tapered pin into andalong a tapered inner surface of the tapered opening causing chucking orbinding.
 14. The fluid infusion system of claim 13, wherein the taperedpin and the tapered opening are configured to continuously slide along atapered inclined interface to compensate for wear and maintain a bindingor chucking condition that absorbs slackness or looseness resulting froma gradual wear of the tapered opening by contact with the tapered pin.15. The fluid infusion system of claim 12, wherein the E-clip retainerprovides a pin counterforce to generate a chucking force.
 16. The fluidinfusion system of claim 12, wherein the opening in the recess of thehandle comprises a tapered opening having a tapered inner surface with ataper that corresponds to a taper of the tapered pin.
 17. The fluidinfusion system of claim 12, wherein the tapered pin comprises a taperedportion and a cylindrical portion and wherein the cylindrical portion isdisposed within the opening in the outer portion of the door housing.18. The fluid infusion system of claim 17, wherein the tapered portionof the tapered pin is partially disposed in the opening in the recess ofthe handle and extends from the opening in the recess of the handle intothe recess.
 19. The fluid infusion system of claim 18, wherein thetapered pin comprises a tapered portion having a taper of approximatelytwo degrees.
 20. The fluid infusion system of claim 11, furthercomprising a threaded extraction hole in the tapered pin.